1 / 29

Measurement System and Conversions in Scientific Notation

Learn about the importance of measurement, different types of measurement, tools used to measure, units of measurement, and how to convert between units using the SI system and scientific notation.

emmettd
Download Presentation

Measurement System and Conversions in Scientific Notation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 1. If one pencil is 5.2 paper clips long, then how many paper clips is 3 pencils? 2. Re-write this number in scientific notation: 93,000,000 miles Bell work:

  2. What do we need to measure? What tools/instruments do we use to measure? Linear: length, width (distance) Area: Volume: Mass: Weight Time Temperature Ruler Micrometer Graduated cylinders Balance / scale Stop watch Thermometer Quantitative Data What units do we measure in? How do we read and record measurements properly? Universal Standard Units: Meter (length) Liter (volume) Gram (mass /weight) Celsius (temperature Use same scale (metric) NO ENGLISH UNITS! Use decimal places Accuracy and Precision Significant figures Scientific Notation Direct and Indirect measurements

  3. To make sense, all measurements need both . . . Suppose we wanted to measure a 2 x 4 for building a house. Numbers by themselves don’t make sense. Units by themselves don’t make sense. A Number and a Unit! A board is 350 long . . . . A board is meters long . . . . Any Ideas? Whydo we need to be able to measure things?

  4. Length: measures distance between objects Volume: measures the amount of space something takes up Mass: measures the amount of matter in an object In SI the basic units are: • Length is the meter • Mass is the gram • Volume is the liter (liquid) • Temperature is Celsius Basic Types of Measurement

  5. Measurement System Comparisons All Measurement systems have standards. Standards are exact quantities that everyone agrees to use as a basis of comparison.

  6. Measurements are easily understood by all scientists • Measurements are easier to convert than the English system Why use the SI System? In the U.S. we use the English or Standard System, most of the rest of the world uses the Metric or SI System. Scientists use the SI System worldwide because: The SI (International System of Units) system is the measurement system used by scientists.

  7. Map of Countries using English Units U.S. Burma Liberia

  8. Length: measures distance between objects Volume: measures the amount of space something takes up Mass: measures the amount of matter in an object Other Types of measurement include: • time • temperature • density • pH Basic Types of Measurement

  9. This system works with any SI measurement. The UNIT becomes whichever type of measurement you are making. (mass, volume, or length) It is the same system regardless if you are measuring length, mass, or volume. The SI System uses the following prefixes:

  10. It works for all types of measurement. If you’re measuring . . . Length then it is the meter (kilometer, decameter, etc.) Mass then it is the gram (centigram, milligram, etc.) Volume then it is theliter (deciliter, hectoliter, etc.) centi gram The first part of the term indicates the amount, the second part indicates the type of measurement.

  11. Unlike the English system converting in the SI System is very easy. For Example in the English system if you wanted to know how many inches in 2 miles what would you do? Take the number of miles (2). Multiply it by the number of feet in a mile (5,280). Multiply that by the number of inches in a foot (12). How does converting units work? ANSWER: 126,720 inches in 2 miles

  12. For example in the metric system if you wanted to know how many centimeters were in 3 meters, what would you do? Find the unit you have (meters). Find the unit you are changing to (centimeters). Count the number of units in-between (2). Move the decimal point that many spaces, in the same direction you counted (right). The SI system is much easier. 3 meters = 300 centimeters Kilo Hecto Deca UNIT Deci Centi Milli

  13. More Conversions . . . 2,321.0millimetersto meters = 2.321meters 521.0grams to hectograms =5.21 hectograms NOTE:The digits aren’t changing, the position of the decimal is. In the English system the whole number changes! Kilo HectoDecaUNITDeciCentiMilli

  14. Things to Remember • All measurements need a number and a unit! • Basic units of Measurement (meter, liter, gram) • How to convert metric units

  15. Precision is a description of how close measurements are to each other. Accuracy is comparing your measurement to the actual or accepted value. Precision and Accuracy

  16. Measurement Review • Measurements need a number and a unit! • Basic units of Measurement(meter, liter, gram) • How to convert metric units • Be able to make basic measurements of volume, length, and mass • Vocabulary words

  17. State the same measurement in two different units length 10.0 in. 25.4 cm

  18. Conversion Factors Fractions in which the numerator and denominator are EQUAL quantities expressed in different units Example: 1 in. = 2.54 cm Factors: 1 in. and 2.54 cm 2.54 cm 1 in.

  19. How many minutes are in 2.5 hours? Conversion factor 2.5 hr x 60 min = 150 min 1 hr cancel By using dimensional analysis / factor-label method, the UNITS ensure that you have the conversion right side up, and the UNITS are calculated as well as the numbers!

  20. Sample Problem • You have $7.25 in your pocket in quarters. How many quarters do you have? 7.25 dollars 4 quarters 1 dollar = 29 quarters X

  21. A rattlesnake is 2.44 m long. How long is the snake in cm? a) 2440 cm b) 244 cm c) 24.4 cm Kilo HectoDecaUNITDeciCentiMilli

  22. Solution A rattlesnake is 2.44 m long. How long is the snake in cm? b) 244 cm 2.44 m x 100 cm = 244 cm 1 m

  23. Amount of People in the World. • There are 6,900,000,000 people in the world. • What is a better way to write this HUGE value? • Scientific Notation • 6.9 X 109 People • Why are we able to write the number like this?

  24. 11 11 cm 11. cm 11.0 cm 11.00 cm 101 101.0

  25. Significant Figures – long story short, this is how well you measured something. The most confusing parts are the zeros • Rules • If there is a decimal point AND non-zeros before and after it, then all numbers are significant Ex: 45.65cm • If the number is not greater than 1 all zeros up to the first non-zero are not significant, but everything else after that is significant. Ex: 0.00560cm • If there is no decimal, any non-zero numbers are significant, as well as any zeros that are in between non-zeros. Ex: 30560cm

  26. Sig-Fig “Box Method” • Step 1 • Draw a box aroundALL nonzero digits, beginning with the leftmost nonzero digit and ending with the rightmost nonzero digit in the number. • 0.0123012300   • Step 2 • If a decimal is present, draw a box around any trailing zeros. • 0.01230123 00   • Step 3 • Consider any and all boxed digits significant. • 0.01230123 00 9 sig. figs.

  27. How many significant figures are in the following: • 203.4 • 7600 • 0.000035 • 7600. • 760.00 2 5 4 2 2

  28. 1. It takes 4.3 pencils to make a book. How many pencils does it take to make 18.3 books? _____pencils__ x ______books___ = 1 book • 3.2 beans x 5 pencils = 1 pencil rug 4.3 18.3 Bell work:

  29. Convert 626 cm to meters: __1m____ x ________ = _______ m 2. How many significant figures in: 5280 _____ 52.80 _____ 100 cm Bellwork:

More Related